The present disclosure relates to a semiconductor storage device in which a plurality of memory modules having a low power consumption mode are formed.
When a low power consumption mode set in a semiconductor storage device is cancelled, power supply is started to a circuit to which the power supply has been stopped and an operation of the circuit whose operation has been stopped is restarted, so that an inrush current occurs in the circuit and a ground level rises in an undesired manner. This may cause a failure due to electromigration or may cause a malfunction due to variation of a logical threshold level. In particular, in a case in which storage capacity of the memory modules mounted in the semiconductor storage device increases, when a low power consumption state of a large number of memory modules is cancelled, a particularly large inrush current occurs. Various techniques for alleviating the inrush current that occurs when the low power consumption mode is cancelled are proposed.
In this regard, Japanese Unexamined Patent Application Publication No. 2013-25843 proposes a method which cancels the low power consumption mode by delaying a control signal and sequentially propagating the control signal to post stage memory modules.